this little program measures and displays the sample rate of a mouse. the sample rate (in Hz) tells how often (per second) the mouse sends
information to your computer.

there are some utilities to change the sample rate of ps/2 mice (the sample rate of serial and usb mice can't be changed afaik). this program is
useful to verify the effects of these programs. you find a collection of these utilities e.g. on the mouse resouce page of blue's news, a very good 3d game related news site.

the standard sample rate of serial mice is 40Hz, ps/2 mice are also sampled with 40Hz on windows 95/98 but with 60Hz on windows nt. mice with usb
interface are sampled 125 times/sec, but unfortunately they only work with windows 98 and windows 2000.

40 or 60Hz is not very much. if you move your mouse quickly you will see that the mouse pointer doesn't follow your movement smoothly but instead it
will jump from position to position. in 'normal' windows applications that 'normally' doesn't matter, 40 or 60Hz is enough for most people (as long as they haven't tested 200Hz :-), but there is one kind of programs
which suffer from a low sample rate: 3d games!

3d games? yes. imagine you bought a fast pc, a nice 3d accelerator and are playing your favorite action game. your graphics hardware is often
capable of displaying 80, 100 or even more fps (frames per second) in some scenes. but when you turn using the mouse, the game can only update your position inside the 3d environment after it receives a new position
from the mouse. and this happens only 40 or 60 times a second! so on some frames the game will receive one (or more if the scene takes long to render) mouse sample and on other frames not even one. this results in a
very jerky movement. this is also the reason, why many 3d games offer you to enable a 'mouse filter'. this filter calulates the average of some mouse samples and will assign every rendered frame a calulated mouse
sample. this will smooth the movement very well but results in some lag, i.e. it takes a while for the game to react on your mouse movements.